Variable air condenser



March 19, 1929. G. PACENT ET AL VARIABLE AIR CONDENSER Filed Aug. 29, 1925 2 Sheets-Sheet March 19, 1929.

L. G. PACENT ET AL.

VARIABLE AIR CONDENSER Filed Aug. 29, 1925 2 Sheets-Sheet 2 ITH/ 7 5 GPace/rd? WZF'GO gym Patented Mar. 19, 1929.

UNITED STATES PATENT OFFICE.

LOUIS G. PACENT, OF WINFIELD, AND CARL F. GOUDY, OF FLUSHING, NEW YORK, AS-

SIGNORS TO PACENT ELECTRIC CO., INC, OF NEW YORK, N. Y., A CORPORATION OF NEW 7 YORK.

VARIABLE AIR CONDENSER.

This invention relates to variable air-condensers commonly employed in radio-receiving apparatus, which condensers include alternating fixed and movable plates adapted 5 to be brought into overlapping relation, more or less, to effect capacity variation.

The object of the invention is to provide a straight-line frequency condenser of S1111- ple, durable, compact and inexpensive con- 1 struction, which, amongst other advantages,

meets the requirements of low loss design.

The invention comprises novel structural features and combinations of parts which will be hereinafter described and claimed.

In the drawings- Figure 1 is a sectional elevation of a variable air-condenser embodying our invention.

Fig. 2 is a vertical section thereof, on the line 2-2 of Fig. 1.

Fig. 3 is a perspective view of the associated rotor and stator plates, the base or heel of the stator-being in section, and the upper or toe supporting clipfor the stator being illustrated as removed.

Fig. 4. is a similar view of a slotted strip which ties and spaces the stator plates at their upper or toe portion.

Fig. 5 is a similar view of a slotted plate for the base or heel of the stator.

6 is a similar view of a basal clip for the stator.

Fig. 7 illustrates an elongated bearing member for the rotor shaft, and also, adjacent thereto, a stop member which co-acts 35 with a projecting pin on the bearing member to determine the limit of rotation of the shaft.

Fig. 8 is a perspective view of a spacing head. I i

Fig. 9' is a transverse section rotor shaftand its bearing, showing the relation of the pin and stop member, as on the line 99 0f Fig. 1.

Fig. 10 is a perspective View of a gland 45 nut hereinafter referred to.

Referring to the drawings, designates the stator plates, and 16 the rotor plates arranged in alternation therewith. The rotor plates are fixed in spaced parallel relation on a shaft 17, by actuation of which they can be overlapped, more or less, with the complemental stator plates in order to effect the capacity variation required to tune a radio frequency circuit to resonance.

through the In the construction herein illustrated the r shaft 17 is rotatable in an elongated bearing constituted by a single mounting hub 18 located at one end of the device and extending through an orifice in the panel 19 of a cabinet. The shaft has affixed thereto an exterior concentric dial 20 and an operating knob 21, which dial is preferably calibrated in kilocycles.

The stator plates are of the general configuration shown in Figs. 2 and 3; that is to say, each plate is an elongated member having a horizontal basal edge or heel, a vertical front edge and a vertical and curved rear edge which terminates at the top of the front edge. This front edge is formed'with a suitable recess 22 near the heel of the plate to permit the free passage of the rotor shaft. The rear edge of the plate is provided with outwardly pro ecting lugs 23, 24, respectively, and the heel portion is provided with a pair of similarly projecting lugs 25.

The stator. plates are assembled in spaced parallel relation and are securely held in place by means of metal tie plates 26 having slots 27 therein which correspond with and snugly receive the lugs 23, 24: of the respective plates, which lugs extend through the slots of the tie plates and are clenched upon and soldered to the outer surfaces of the latter plates. In addition,- a base plate 28 having two rows of slots 29 therein corresponding with the lugs 25 of the stator plate is applied to-the heel of the stator in such manner that the lugs 25 project through the slots. The outer ends of these lugs 25 are clenched upon and soldered to the outer surface of the base plate. By this simple construction and arrangement of parts the whole stator assembly is structurally rigid and presents a continuous unbroken path of extremely low resistance to the flow of current through the condenser.

Clips 30, 31 of sheet metal are applied respectively to the base plate 28 and the upper tie plate 26, and the edges of such clips are crimped upon the longitudinal edges of the adjacent plates, as at 32 and 33, respectively. These clips are secured to blocks 34, 35, respectively, of insulating material, the upper or toe clip having an outwardly projecting perforated lug 36 to which the block 35 is fastened bymeans of a screw 37, and the basal clip 30 being perforated and channelled to receive the shanks and nuts respectively of bolts 38 by means of which the latter clip is fastened to the block 34. The insulation blocks 34, 35 extend beyond one side of the stator and are secured to the respective ends of a substantial supporting member which is rigidly secured to, but spaced from, the panel of the cabinet. This member comprises an upright bar 39 having an enlarged or expanded basal portion 40, and it is preferably stamped from heavy sheet brass suitably ribbed to ensure the maximum stiffness with minimum weight, although it may, if desired, be a casting of proper shape. The single supporting member is maintained inspa-ced relation to the panel by a flanged hollow head 41 which is fastened or otherwise secured to the inner side of the panel, such member being clamped against the head by means of the single mounting hub 18 which extends through an aperture in the panel and affords the elongated bearing, hereinbefore mentioned, for the rotor shaft. The mounting hub is exteriorly threaded and is screwed into a correspondingly threaded aperture in the spacing head 41; and an externally threaded flange 42 at the inner end of the hub bears against the opposing surface of the supporting member. A nut 43 on the outer end of the mounting hub 18 is screwed against the exterior of the panel to effect and maintain the rigid connection of the assembled parts just described.

The rotor plates 16 are of the general semiovate form shown in Figs. 2 and 3, and their common axis of rotation is located adjacent their larger ends. Hence the rotor plates being in eccentric relation to the center line of the stator permit the efficient overlapping relation of the complementary plates. The forward edge of each rotor plate 16 has a suitably disposed perforation therein for the reception of the shaft 17, and such edge is also provided with a projection 44 having an outwardly extending lug 45. lVhen the rotor plates are properly assembled on the shaft 17 in alternate relation with the stator plates, a slotted strip 46 is applied to the lugs and the latter are then clenched and coated with solder, thus rigidly uniting and spacing the upper portions of the rotor plates. These rotor plates are spaced apart on the shaft 17 by interposed washers 47; and nuts 48 which are screwed on the inner end of the shaft 17, effectively bind the assembled rotor plates and washers together and against a flanged collar 49 that is positioned on the shaft adjacent the threaded flange 42 of the mounting hub. The correct position of the collar 49 on the shaft is ensured by a suitable stop composed preferably of a split ring 49 which is fitted in a suitable groove in the shaft so as to receive a socket in the flanged end of the collar when the latter is slid along the shaft preparatory to the assembling thereon of the rotor plates and washers. A protective gland nut 50 screwed on the flange 42 encircles the collar 49, and a tensioning washer 50 intel-posed between the gland nut and the flange of the collar 49 holds the latter firmly against the ring 49. The flange of this collar 49 is peripherally reduced, as at 51, to provide two spaced apart shoulders 52 between which extends a rigid stop pin '53 which is fastened, as by riveting, to the supporting member and the spacing head, and extends throughan aperture in the flange 42 of the mounting hub, as clearly seen in Fig. 1. The respective shoulders 52 abut against the opposing stop pin, and thus positively determine the maximum range of rotation of the rotor, when the knob 21 is manipulated.

From the foregoing it will be seen that a condenser embodying our invention is characterized by compactness, strength and lightness, together with ease of assembly and simplicity of'operation. The lightness of the structure permits the use of a single hole mounting in the panel of the cabinet, and in consequence the provision of a single elongated hearing by means of which accurate alignment of the rotor shaft is maintained and its manipulation facilitated. The complemental rotor and stator plates are accurately spaced and maintained in parallel relation, and, since the rotor is grounded and in continuous electric connection with the rigid end supporting member and the latter is connected with the stator by only two small pieces of dielectric material at its respective ends, the absorption losses are negligble. Hence our condenser meets all the requirements of low loss design.

It is obvious that a succession of the improved condensers can be readily mounted on a common'base and the adjacent ends of the rotor shafts mechanically connected.

lVe claim 1. A variable air condenser comprising a single supporting member, a mounting hub projecting from one side thereof, insulation supports extending from the opposite side of and wholly supported by said supporting member, a stator including an assembly of parallel elongated plates secured to said insulation supports, and a rotor including an assembly of parallel elongated plates and a shaft having its bearing in the said mounting hub.

2. A variable air condenser comprising a single supporting member, a mounting hub located betweenthe ends of said member, in sulation supports extending from the ends of and wholly supported by said member, a stator including an assembly of parallefelongated plates supported by and between said supports, and a rotor including an assembly of parallel elongated platesand a shaft having its bearing in the said mounting hub.

3. In a. variable air condenser, a stator comprising parallel elongated plates having heel and toe portions provided with edge projecting lugs, tie plates having spaced apart slots through which the said lugs project and are clenched atithcir outer ends, and clips afiixed to said plates, a supporting member at one end of the stator, insulation bars extending'from the respective ends of said member and attached to the respective clips, a single mounting hub on said member a ffording an elongated shaft bearing, a rotor shaft mounted in said bearing, and elongated rotor plates mounted on said shaft in alternation with the stator plates.

4. In a variable air condenser having alternating stator and rotor plates, a single supporting member, insulation supports for said stator plates extending from one side of and wholly supported by said member, a shaft upon which the rotor plates are mounted, spacer washers between the adjacent rotor plates, a collar mounted on the shaft adjacent said supporting member and having spaced apart shoulders, means for binding the rotor plates and washers together and against the collar, a single mounting hub projecting from the supporting member and affording an elongated bearing for the said shaft, and a fixed stop pin projecting between the shoulders of the collar.

5. In a variable air condenser having alternating stator and rotor plates, a single supporting member, insulation supports for said stator plates extending from one side of and Wholly supported by said member, a shaft upon whicl' the rotor plates are mounted, a stop member on said shaft, spacer washers between the adjacent rotor plates, a flanged collar mounted on said shaft in contact with the stop member, means for binding the rotor plates and washers together and against the collar, a mounting hub projecting from the supporting member and affording an elongated bearing for the said shaft, a gland nut screwed on said hub and encircling the collar, and a tensioning washer interposed between the gland nut and the flange of the collar.

6. In a variable air condenser having alternating stator and rotor plates, a single sup porting member, insulation supports for said stator plates extending from one side of and wholly supported by said member, a shaft upon which the rotor plates are mounted, a stop member on said shaft, spacer washers between the adjacent rotor plates, a flanged collar mounted on said shaft in contact with the stop member and having spaced apart shoulders in the flange, means for binding the rotor plates and washers together and against the collar, a mounting hub projecting from the supporting member and affording an elongated bearing for said shaft, a gland nut screwed on said bearing and encircling the collar, 21 tensioning washer interposed between the gland nut and the flange of the collar, and a fixed stop pin projecting between the shoulders of the collar.

7 The combination with a panel having an aperture therein, of a variable air condenser mounted on the panel and'comprising alternating stator and rotor plates, a single supporting member, insulation supports for said stator plates extending from one side of and wholly supported by said member, a shaft upon which the rotor plates are mounted, a flanged and threaded mounting hub proj ecting from the supporting member through the aperture of the panel and affording an elongated bearing for the shaft, and a clamp nut on the outer end of. the mounting hub.

8. The combination with av panel having an aperture therein, of a variable air condenser mounted on the panel and comprising alternating stator and rotor plates, a single supporting member, insulation supports for said stator plates extending from one side of and wholly supported by said member, a spacer between said member and the inner side of the panel, a shaft upon which the rotor plates are mounted, a flanged and threaded mounting hub projecting from the supporting member through the spacer and the aperture of the panel, and a clamp nut on the outer end of the mounting hub.

9. In a variable air condenser, a stator comprising parallel elongated plates having heel and toe portions provided with edge projecting lugs, tie-plates having spaced-apart slots through which the said lugs project and are clenched at their outer ends, and toe and heel clips applied to the respective tie plates and having their edges crimped upon the longitudinal edges of the tie plates.

LOUIS G. PACENT. CARL F. GOUDY. 

